Before transitioning, I was attracted to men and women, maybe even a little biased towards men. My attraction to men sharply dropped off after I began hormone therapy and started feeling like a woman. Now I consider myself exclusively lesbian. My desire for male affection was almost entirely driven by gender dysphoria and a desire to "feel like a woman" romantically and sexually.
My pre transition attraction to women was hampered a lot by the idea that I would be a guy with a girl, and be expected to conform to heterosexual expectations for how a man should date and have sex with a woman. I never wanted to penetrate, and my fantasies about women only extended to oral sex and them penetrating me with toys. When I realized that I could be with a woman as a woman, it was an absolute game changer and I never looked back.